Design of planar reinforced concrete D regions with nonlinear finite element analysis

This paper is concerned with the design of reinforced concrete structures like deep beams and squat shear walls which are examples of so called Disturbed or D regions in which plane sections do not remain plane after loading. Over the past few decades, a great deal of effort has been expended in developing increasingly sophisticated procedures for the numerical analysis of reinforced concrete structures. Despite this, designers tend to use rules of thumb or simplified strut and tie methods (STM) for the design of D regions in reinforced concrete structures. This paper seeks to bridge this divide by presenting a semi-automated nonlinear finite element based procedure for the design of D regions in which the assumption of plane stress is valid. The procedure is intended as an alternative to STM. It finds the minimum area of reinforcement required to satisfy user specified design constraints subject to practical detailing considerations.